164; Dr. T. Andersoh on certain Products of Decomposition 



tion of the products of its decomposition ; but these must also 

 be peculiar, as I could not distinguish the presence of acroleine 

 during any period of the distillation of an oil with sulphur. 



The product of the distillation of oleic acid was in the form 

 of a reddish-brown oil, having an extremely nauseous odonr, 

 in which that of sulphuretted hydrogen was apparent. When 

 rectified, this sulphuretted hydrogen was driven off, and the 

 first portions which distilled were perfectly transparent and 

 colourless. As the process continued, however, the products 

 became gradually darker in colour, and the last portions which 

 distilled became semisolid on standing, from the deposition of 

 a quantity of wiiite crystalline plates. These were separated 

 by filtration through cloth, expressed strongly, and purified 

 by successive crystallizations from alcohol, until they were 

 entirely free from smell and colour. The product was then 

 in the form of white pearly scales, which possessed acid pro- 

 perties, and were totally insoluble in water; they were not 

 therefore sebacic acid, no trace of which could be discovered 

 among the products, but, on the contrary, possessed all the 

 properties of margaric acid. These crystals were obtained 

 from quantities of oleic acid, prepared at different times, and 

 with the greatest possible care, and must have been formed 

 during the decomposition. In order however to set this point 

 at rest, some of the same oleic acid was distilled alone, when 

 abundance of sebacic acid was obtained, and the latter portions 

 of the rectified product did not deposit any crystals on cooling, 

 but remained perfectly fluid. As this solid acid is produced 

 only in comparatively small quantity, and I was unable to 

 obtain enough of oleic acid, I made use, in preparing it on the 

 large scale, of pure almond oil, which, according to Schiibler 

 and Gasserow, is entire!}' free of margarine. The oil which 

 I employed was expressed specially for these experiments, at 

 a temperature slightly above 32°; and in order to satisfy 

 myself of the absence of margaric acid in the products of its 

 ordinary decomposition, a quantity was distilled alone, and 

 the product rectified. The latter portions being collected 

 apart did not deposit margaric acid ; and this 1 have also 

 found to be the case with the ordinary almond oil of com- 

 merce, in the expression of which a moderate degree of heat 

 is employed. 



In distilling the oil and sulphur on the large scale, it be- 

 came impossible to perform the process by the simple admix- 

 ture of the substances, the frothing being so great as inevitably 

 to expel the materials from the retort. After a trial of various 

 methods, I found it most convenient to employ the apparatus, 

 of which this is a sketch. The oil was introduced into a large 



